Lung cancer is the leading cause of cancer-related death in the US, and smoking cessation is the main modifiable risk factor for lung cancer. In 2011 the National Lung Screening Trial (NLST), a large multicenter randomized controlled trial, found that screening for lung cancer using a special type of lung scanning called low dose CT scanning resulted in lower rate of lung cancer deaths among current and former smokers screened with low dose computed tomography (LDCT) compared to chest x-rays. This was the first high- quality study to prove that screening can prevent death from lung cancer. Based on these findings, specialty groups have now recommended that screening with LDCT be offered to at-risk patients. However, concerns have been raised about the potential adverse consequences of widespread screening including: a) whether screening could discourage current smokers from quitting by providing false reassurance; and b) whether patients can be informed about the potential benefits and potential harms associated with screening. This issue is of particular concern for patient populations with limited health literacy. Informed decision-making is critical because screening identifies a large number of benign lung nodules (false positives) that require further testing and procedures. This can put patients at risk of harms they may not have experienced had screening not been performed. Our objective is to develop an informed decision making tool for use in counseling patients who are potentially eligible for lung cancer screening. First, we will convene an expert panel to help us develop candidate messages for the tool. Second, conduct focus groups of patients who are current smokers and who are either eligible for lung cancer screening or have had an LDCT screening test in order to get their perspectives on these messages and help us improve them. We will also ask them how thinking about getting screened for lung cancer might also help them decide to attempt to quit smoking. Third, we will interview physicians to learn how they would use the tool to counsel patients about screening and smoking cessation in practice. Next, we will refine the tool by interviewing individual patients (not in a group) to us make sure the final messages are clear. Finally, we'll conduct physician-patient role plays to test out the final decision making tool an to see how long it takes to deliver. With its focus on smoking and cancer screening, the proposed research is highly relevant to the prevention objectives of the Centers for Disease Control and the National Center for Chronic Disease Prevention and Health Promotion. It will result in a tool that is ready to be tested in a clinical trial. The trial will test whether this tol can effectively promote informed decision-making and smoking cessation in practice. .